I think I remember SmileBoom mentioning that the European version will release about the same time SmileBASIC for Wii U is released. However, we haven't heard much about either for quite a while, so I'm a little worried...
I can only suppose they're working hard to bring us those things.
In the same tweet that Kobayashi announced SB was back on the US eShop, he said "Europeans wait a little bit longer!" Or something to that effect. So they've been working on it this entire time,they just haven't said anything.
Patience is key.